The story begins by introducing Freddie Quell (Joaquin Phoenix), a disturbed sailor who just got back from serving in WWII. He’s been discharged due to a medical condition he suffered at war (it’s implied his appendix burst), so now he spends his time getting drunk on a beach where he is seen wrestling with other sailors and having sex with a lady they made out of sand (complete with sand boobs/vagina). Another interesting quirk about Freddie he brews his own alcoholic concoction made from coconut juice, booze and gasoline. The PTSD Freddie suffered from the war causes him to be prone to violent outbursts and obsessed with sex.
When he gets back from the war, the Navy places Freddie in a mall photographer job so he can find some purpose. At first, the job is tolerable for him he finds time to make his strange alcohol in the break room and also succeeds in seducing a jacket-selling mall employee. When she rebuffs his advances for sex, he takes his anger out by annoying a customer and provoking him into a fight.
After being fired, he gets a job working on a farm. However, this is also temporary after he shares some of his homemade booze with another farmer the farmer dies from alcohol poisoning, and Freddie is chased off the farm. With nowhere else to go, a belligerent Freddie seeks refuge on a boat shipping off with a large party on it.
The next morning, he wakes up below on one of the boat’s lower levels. He is brought into an office and “reintroduced” to Lancaster Dodd (Philip Seymour Hoffman), a distinguished man with many talents and is referred as “The Master”. He has written a book outlining his teachings and bizarre claims; and he traveling the country, collecting info for a second book. Dodd claims Freddie asked for a job the previous night, but Freddie blacked out and doesn’t remember. Dodd offers him work on the boat after hearing his sailor experience -- he also asks Freddie to make more of his “magic potion” (the homemade booze). At first, Freddie is thrown back by Dodd’s interesting personality, but he eventually agrees to work for him and to also make a drink similar to his something much stronger.
Dodd invites Freddie up to the bow with him, where his daughter Elizabeth (Ambyr Childers) is about to be married to Clark (Rami Malek), another devout follower of Dodd’s. Through the wedding and reception, Freddie learns more and more about Dodd although he’s charismatic and very persuasive with his words, he also seems to have a hidden distrust for strangers. He still has a large group of supporters his biggest one obviously being his wife, Peggy Dodd (Amy Adams). Throughout the movie, Peggy is the one to motivate her husband whenever he reaches high levels of uncertainty.
As Freddie begins working on the boat, he is also provided the “supplies” requested to make Dodd’s drink the one peculiar ingredient being paint thinner. Freddie drinks the new alcohol with Dodd, who approves. Dodd then invites Freddie to be his “guinea pig” for a test he administers called Processing which basically involves someone asking a patient numerous psychological questions over and over again until they crack and let go of the past. In a very intense scene, Dodd repeatedly drills Freddie with questions in this, Freddie reveals his dad is dead, and his mother is in the nuthouse. He was also in love with a girl named Doris, but abandoned her by enlisting in the Navy. Dodd is skeptical of Freddie’s answers, but things get kicked up a notch when they go for “Level 2” of questioning. Things get very personal at one point, Freddie even admits to sleeping with his aunt because he “was drunk and she was lookin’ good.” Dodd realizes how messed up he really is.
Processing leaves an effect on Freddie when the boat docks, he begins to travel with Dodd and his followers, The Cause. He helps spread the teachings, which center around the belief that humans are al living past versions of themselves. While in Philadelphia, they temporarily settle at the house of devout Cause follower Helen Sullivan (Laura Dern), and with her help Dodd is taken to Mildred Drummond (Patty McCormack). During a dinner party, Dodd conducts a round of Processing on a stressed Mildred while many onlookers watch. One man in particular laughs at Processing and questions many of Dodd’s beliefs, such as how this can possibly cure diseases like leukemia. Later that night, Freddie goes to the man’s house and assaults him.
Freddie’s behavior makes the rest of the followers worried, but Dodd insists that “saving” him is an important mission. Peggy, being the devoted wife that she is (at one point she’s shown helping Dodd masturbate while encouraging his beliefs really eerie scene), asks Freddie to quit drinking. Freddie agrees, but of course doesn’t take her seriously he only listens to his master. Meanwhile, Dodd’s son Val (Jesse Plemons) grows tired of seeing his father treat Freddie so well and decides to let Freddie in on a secret: Dodd is making all of his teachings up as he goes along. Of course, Freddie doesn’t believe suddenly, the police show up and arrest Dodd for practicing medicine without a license. The followers cry outrage and Freddie assaults a few cops. He’s also taken into jail, where he destroys his jail cell (toilet and all) and bangs his head on the bed Dodd calmly tells him “Your past life was in jail millions of years ago.” Freddie yells at him, accusing him of being a fake. This doesn’t sit well with Dodd they have another intense shouting match where Dodd asks Freddie to trust him so he can save him. Since Freddie has no one else to turn to, he reluctantly stays obedient to Dodd.
The two get released from jail, but the followers are now beginning to believe Freddie is an undercover cop….or insane. Regardless, Freddie continues his tests with The Cause. One strange test has him walking to a wall with his eyes closed, touching it, then walking the other way, and touching the window. Another test involves him subjected to insults from Clark. Although these tests seems bizarre at first, Dodd shows the tests are for Freddie to dwell on the man he “used to be” one last time before he lets go. Freddie still doesn’t get it he only grows more frustrated.
The Cause travels to Phoenix, where Dodd plans to publish his second book. Things get off to a rocky start when the publisher also begins to question some of the books facts and just like the previous non-believer, Freddie beats the crap out of him too. Helen Sullivan also finds a major change in the book's publication something like the phrase “it is certain” has been changed to “it is believed”. When this becomes too much, Dodd yells at her “WHAT IS YOUR POINT?” It is clear Dodd is losing his grip on his own teachings, even with Peggy borderline-obsessing over keeping him on the right track. Dodd brings Freddie, Elizabeth, and Clark out to desert for another exercise called “Pick a Point” which basically involves you riding a motorcycle out to an unseen point in the desert, find something you weren’t supposed to find, then return. During his turn, Freddie decides he’s had enough with The Cause and drives out of the desert, abandoning them.
Freddie returns to his hometown and tries to find his lost love Doris in an attempt to rekindle their love. When he shows up at her house, he realizes that only her mother lives here. It’s revealed that seven years have passed since Freddie abandoned Doris, and she’s now happily married in Alabama. Of course, Freddie is angry, but he does get some relief knowing that Doris is happy.
Some time passes. With nowhere to go, Freddie spends his days having sex with random girls and getting drunk in movie theaters. He receives a call from Dodd, who asks to meet him in London. Freddie reluctantly goes, and is surprised to learn that The Cause has set up headquarters in a huge building in London. Freddie has one last word with Peggy, who insists he has no intention of changing his life around. Freddie then meets with Dodd, who gives him a choice of staying with The Cause the rest of his life so he can be fully “cured”, or to leave and never come back. Freddie chooses to leave, deciding he would rather attempt to live life without a master. Dodd admires this, and bizarrely sings Freddie a song as his farewell. Freddie tearfully bids his former master goodbye.
The movie ends with Freddy in an English pub, and hooking up with a local girl. After they have sex, they are, more or less, laying together and he's jokingly giving her the same, "Processing," that Dodd gave him.
There is a quick flashback to his time back in the Navy, on the beach cuddling with the sand sculpture woman. In the end, The Cause did seem to have an effect on Freddy's life, and maybe even a positive one. He began the movie only being able to "sleep" with a fake woman. Throughout the movie he got rebuffed by real women because of his intolerable nature. Finally, in the end, he became "tolerable" enough that he did get laid.
(Thanks for the update, Jesse)
You can send in your spoiler to other movies by going here.